Class Notes NCERT Solutions for CBSE Students
FINDING PERCENTAGE
A. Finding the percentage as a number
(a) Arjun’s mother bought a pair of shoes for him at a sale. The shoes coast Rs. 300, but she got it at 25% less than that. How much money did she save?
We need to find 25% of Rs. 300
Step 1. Write the per cent as a fraction: 25/100
Step 2. Multiply by the quantity: 25/100 × 300 = 75
Answer: Arjun’s mother saved Rs. 75.
(b) What is 4% of 60 meters?
B. Finding What per cent one number is of another
(a) Ankita got Rs. 225 from making and selling Diwali card during the school fete. She spent Rs. 90 on buying a present at the fete for her mother. What percentage of her money did she spend?
To find what per cent 90 is of 225:
Step 1. Express 90 out of 225 as a fraction → 90/225
Step 2. Change the fraction into a percentage by multiplying by 100 → 90/225 × 100 = 40%
Answer: Ankita spent 40% of what she earned on buying a present for her mother.
(b) What per cent is 50 g of 1 kg?
Step 1. Make both the units same → 1 kg = 1000 g
Step 2. Express 50 g out of 1000 g as a fraction → 50/1000
Step 3.Change the fraction to a percentage by multiplying by 100 → 50/1000 × 100 = 5%
Answer: 50 g is 5% 0 1 kg
(c) What per cent is 1 week of 1 month?
(Take one month to have 30 days.)
1 week = 7 days
1 month = 30 days
CHECKPOINT: Use the same units while finding percentages.
